1. Field of the Invention
The present invention generally relates to a color and white filter array, and more particularly to a method of color processing using an RGBW filter array.
2. Description of Related Art
A Bayer filter, as depicted in FIG. 1, is a color filter array composed of red (R), green (G) and blue (B) color filters disposed on a grid of photo-sensors, and specifically configured with a pattern of 50% green, 25% red and 25% blue. The Bayer filter with the photo-sensors forms an image sensor that is commonly used in electronic devices such as digital cameras or camcorders.
As each composing color filter of the Bayer filter passes only one color, information of other colors at each pixel position need be calculated by interpolation. The image sensor with the Bayer filter generally suffers from low sensitivity and low signal noise ratio (SNR). A modified Bayer filter with transparent white (W) filter (commonly called RGBW filter array) is thus introduced to improve sensitivity and SNR. The conventional image sensor with RGBW filter array, however, does not make effective use of the color and white information, and therefore cannot effectively improve sensitivity and SNR while preserving resolution and minimizing color artifacts.
A need has thus arisen to propose a novel scheme of processing the color and white information obtained from the RGBW filter array in order to overcome the disadvantages mentioned above.